First, expand the left side of the equation:
(x−2)(x+1)=x2+x−2x−2=x2−x−2 So the equation is now:
x2−x−2=22x+19 Multiply both sides by 2 to eliminate the fraction:
2(x2−x−2)=2x+19 2x2−2x−4=2x+19 Move all terms to the left side to obtain a quadratic equation in standard form:
2x2−2x−4−2x−19=0 2x2−4x−23=0 Now, we can use the quadratic formula to solve for x: x=2a−b±b2−4ac where a=2, b=−4, and c=−23. x=2(2)−(−4)±(−4)2−4(2)(−23) x=44±16+184 x=44±200 Since 200=100⋅2, we have 200=100⋅2=102. x=44±102 Divide both terms in the numerator by 2:
x=22±52 So the two solutions are:
x=22+52andx=22−52